AVO reported that during 11-15 March seismic activity at Redoubt was low but remained above background levels. On 12, 14, and 15 March clear web camera views showed steam plumes that rose just above the summit. At about 1305 on 15 March, seismic activity increased and about four hours of volcanic tremor ensued. AVO scientists aboard an overflight saw a steam-and-ash plume rise to an altitude of 4.6 km (15,000 ft) a.s.l. and produce minor ashfall on the summit crater floor and down the S flank. The emissions originated from a new vent, located just S of the 1990 lava dome and W of the prominent ice collapse feature near the N edge of the summit crater. About twenty minutes later, a sediment-laden flow occurred from a small area in the ice on the upper part of Drift glacier. Steam plumes were later noted. AVO raised the Aviation Color Code to Orange and the Alert Level to Watch. Clear web camera views on 17 March showed no unusual activity.
Source: Alaska Volcano Observatory (AVO) – “Reports provided courtesy of the Smithsonian’s Global Volcanism Program and the US Geological Survey’s Volcano Hazards Program.”